Command line options
 
VirtualDub supports limited control via command line options.  Allowable switches:
 
· /bsource_dir,dest_dir  adds a batch of jobs to translate from one directory to another, using the current options.  (Note: there are no spaces in the switch.)
· /c clears all jobs in the job list.
· /r runs the job list.
· /sscript_name runs a script.
· /x forces an exit after the job list has run.
 
The order of the switches matters, since switches are run from left-to-right.  Because VirtualDub configuration files are simply Sylia scripts, just like the job list, they can be invoked using the /s option to set the dub processing parameters.  So to do automated processing of video files, you can set the parameters you want and save them in a configuration file, and then have a scheduling program invoke VirtualDub using a command line like this:
 
virtualdub /sparms.vcf /b”f:\ready”,”f:\output” /x /r
 
VirtualDub will then run the script to load parameters, scan the f:\ready directory and add job entries to process files there to f:\output, run the job list, and then exit.
 
Because VirtualDub is a GUI application, any console it is run from returns immediately, even before VirtualDub has finished processing.  This is fine if you want to process in the background, but poses problems in a batch file.  The solution is to use the start command to force a wait:
 
start /wait virtualdub /s”pack indeo5.vcf” /bin,out /x /r
 
This works under both Windows 95/98 and NT4.
 
Finally, if you need more specific control, you can always write a program to generate job scripts and append them onto the virtualdub.jobs file, which is simply text.  You must be careful about the format, or VirtualDub can get confused, but this allows you much greater freedom in file and mode selection.  Then, in a batch file, simply invoke VirtualDub with the /r and /x flags alone to run the job list.